NC0024244_Pretreatment_HWA_Letter_20200310

ROY COOPER
Governor
MICHAEL S. REGAN
Secretary
S. DANIEL SMITH
Director
(sent via email: [e-mail])
Brandon Plyler, Pretreatment Coordinator
City of Albemarle
P.O. Box 190
Albemarle, NC 28002
NORTH CAROLINA
Environmental Quality
March 10, 2020
Subject: Pretreatment Review of Headworks Analysis - Approved
Program: City of Albemarle
NPDES Permit No: NCO024244
Stanly County
Dear Mr. Plyler:
The Pretreatment, Emergency Response, and Collection Systems (PERCS) Unit of the Division of Water
Resources has reviewed the Headworks Analysis (HWA) for the City of Albemarle. This HWA was received
by the Division on November 19, 2019, via email, with additional information submitted by Suez, the City's
consultant, and received on February 20, 2020, via email.
The Division concurs with the HWA calculations for all pollutants of concern, with corrections discussed
below. These approved Maximum Allowable Headworks Loadings (MAHLs), Maximum Allowable
Industrial Loadings (MAILS), and the basis for these values are found on the last page of the enclosed HWA
spreadsheet. The results of the HWA are also listed in the bottom section of the enclosed Allocation Table.
1. Changes to the HWA Approved Today: Please feel free to contact PERCS if you have any questions
about the changes outlined below. All corrected spreadsheets were emailed to you for your files,
and other corrected documents were faxed. Please ensure the POTW's paper and electronic
HWA, AT, and other supporting documents contain these corrected documents, especially the
Allocation Table. As needed, please mark any original documents as "replaced" or "voided."
a. Inhibition Loading Calculations: To calculate inhibition loadings for chromium, copper,
and zinc, PERCS chose to use the average of LTM site -specific aeration basin data which
is more conservative than using the maximum sampling data.
b. Metals Calculator: To calculate pass -through loadings for the metals, PERCS chose to use
the Hardness values that were used in your latest NPDES Permit renewal (documentation
attached).
Over Allocation: The HWA shows over allocation for NH3 and silver based on
uncontrollable. The SIU does not currently have limits for these parameters.
PQL for Silver: Please begin immediately using the PQL of 0.001 mg/I for silver at all LTMP
locations.
D E Q�� North Carolina Department of Environmental Quality I Division of Water Resources
512 North Salisbury Street 1 1611 Mail Service Center I Raleigh, North Carolina 27699-1611
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2. HWA Due Date: The HWA approved today is primarily based on DMR/LTMP data for the period
of March 2017 through June 2019. Unless conditions at the POTW change significantly and thus
warrant an earlier submittal (see Comprehensive Guide, Section 8), the POTW must submit the
following:
i. Updated LTMP due by July 31, 2022, based on NPDES permit renewal.
ii. HWA due by December 31, 2024.
iii. It is noted that the current NPDES permit has new metals limits that do not come
into effect until September 1, 2025. Please use these new limits in your HWA,
with any applicable discussion about the impact on the HWA.
1. Please cc: PERCS on the yearly reports required by Section A. (8) due on
September 1 of each year from 2020 — to 2025.
iv. It is also noted that the POTW is entering into an SOC with the Division to address
collection system inflow and infiltration and WWTP issues. It is understood that
this is not at all related to the POTW's one SIU. Please include a brief update with
your next HWA, especially as it relates to overall WWTP performance.
Federal and State pretreatment regulations require the local delegated pretreatment program to
effectively control and document the discharge of wastewater from Significant/Categorical Industrial
Users to the POTW. It is the POTW's responsibility to ensure that these objectives are consistently met.
Thank you for your continued cooperation with the Pretreatment Program. If you have any questions or
comments, please contact me at [phone] [email: Monti. [e-mail]].
Sin�e9lYdby:
LH-663;74C�4
as:-8174 2
for S. Dame Smith, Director
Division of Water Resources
mh/aIbemarle.hwa.2019
Attachments:
AIbemarleHWA.AT.2019 Final mar10 2010
Documentation of Hardness Data from NPDES Permit Renewal
ec: Central Files (LF)
Wes Bell. MRO
Nadine Blackwell, Suez
PERCS Unit